Healthy food equals lighter mood, study shows

University of Otago psychological scientist Dr Tamlin Conner spreads the word on the benefits of eating more fruit and vegetables. Photo by Stephen Jaquiery.

A new study suggests food changes mood and that eating fruit
and vegetables each day helps keep the blues away.

Eating more fruit and vegetables may make young people
calmer, happier and more energetic in their daily life, the
University of Otago research indicates. Otago psychology
department researcher Dr Tamlin Conner, and Dr Caroline
Horwath and Bonnie White, both of the Otago human nutrition
department, explored the relationship between day-to-day
emotions and eating.

The study, which analysed the consumption of food, and of a
wide range of fruit and of vegetables, including carrots, was
published in the British Journal of Health Psychology
yesterday.

The results showed a strong day-to-day relationship between
more positive mood and higher fruit and vegetable
consumption.

''On days when people ate more fruits and vegetables, they
reported feeling calmer, happier and more energetic than they
normally did,'' Dr Conner said.

She was ''excited about the findings'', which added to a
''really interesting and growing research area'', exploring
links between food consumption and mood.

A total of 281 young adults, with a mean age of 20, completed
an internet-based daily food diary for 21 consecutive days,
rating how they felt and indicating what they had eaten that
day. They were asked to report the number of servings eaten
of fruit - excluding fruit juice and dried fruit -
vegetables, excluding juices, and of several kinds of
unhealthy foods, such as biscuits or cookies, potato chips
and cakes or muffins.

Later analysis showed young people would need to eat about
''seven or eight total servings of fruits and vegetables per
day to notice a meaningful positive change''. One serving of
fruit or vegetables was about the ''size that could fit in
your palm, or half a cup''. Her co-author Ms White suggested
this could be done ''by making half your plate at each meal
vegetables, and snacking on whole fruit, like apples'', Dr
Conner said. She emphasised she was not suggesting dietary
change as an alternative treatment for depression.

But there was ''growing recognition'' that eating more fruit
and vegetables provided benefits for both physical and mental
health.

Choosing to each more fruit and vegetables was ''one small
thing that we can do''.